Lionel Messi was kept off the score sheet by excellent saves from home keeper Diego Marino and he was forced into action by the Argentina ace before the only goal of the match.

Rossi fired home from close range past Victor Valdes after indecision in the Barcelona defense.

Messi had to more efforts saved by halftime but after the break it was Neymar who missed Barca's best chance, blazing over from close range after being set up by Cesc Fabregas.

The home side held out comfortably enough and might have added to their tally when Oscar spurned a fine chance.

But they were left to celebrate a famous victory to move out of the relegation zone.

"We lacked ideas, movement and penetration, but I didn't in any way see a lack of attitude," Martino told AFP after the defeat.

His side will have to regroup ahead of the visit of Manchester City Wednesday in the Champions League, but lead 2-0 from the first leg in the last 16 tie.

The Catalan giants suffered a stinging 6-0 aggregate defeat to eventual winners Bayern Munich in the semifinals of last year's competition but had been in impeccable form under Martino until recent domestic setbacks.

We lacked ideas, movement and penetrationGerardo Martino

Meanwhile free-scoring Bayern have continued their all-conquering form, thrashing fifth-placed Wolfsburg 6-1 in the Bundesliga Saturday, despite the match being tied 1-1 at halftime.